1. Field of the Invention
This invention relates to guides used in the installation of conductive cables on structures wherein dollies are required to guide a cable at an angle or around a deflection.
2. Description of the Prior Art
Heretofore, devices for running a large cable around a deflection or an angular structure have required first a small-diameter rope or leader to begin the installation and thereafter a high strength bullrope or hawser to pull large cables into position. Experience has shown that the larger dollies capable of handling the high tensions induced by deflections or structural angles in the installation of large cables cannot prevent the small lead ropes required from jumping out of a large dolly groove and, in some instances, becoming bound in the spokes thereof. The foregoing is true where, in the past, it has been necessary, particularly at heights of from substantially 45 inches to 400 feet or more, to transfer the bullrope or hawser from the pulley of a small-diameter dolly to the pulley of a dolly having a substantially larger diameter.
Prior cable installation procedures have overcome this problem only by requiring additional personnel and equipment to transfer the bullrope from a small 8-inch dolly to a substantially larger 22-inch dolly. The present invention avoids or eliminates these procedures by providing a means for retaining the small lead rope in large dolly pulley grooves, thereby eliminating the need for a small dolly.
U.S. Pat. No. 5,357,054 to Beckerich relates to a cable installation method and apparatus in which a steel conduit is placed against a column and magnetically held in place by a conduit holder magnetically attached to the conduit and to the column to hold the conduit in proper location while it is clamped to the column by a clamp fastened to the column by a screw. Armored cable is passed over a smoothly contoured guide magnetically secured to bar joists, both at the cable feeding end and at the cable pulling end or drop end to facilitate the pulling of the cable from a supply coil on the floor up and over one bar joist and down another bar joist spaced from it, for connection to the rough-in box. It is submitted that this reference is patentably distinct from the present invention both in the magnetic holder and the absence of a reference regarding the use of dollies to string cables, among other distinctions.
U.S. Pat. No. 4,475,715 to Asplin relates to the use of two spaced generally L-shaped members whose vertical portions have hooked ends that suspend a block from a support cable at a pole location, and a stabilizing bar that abuts the pole to maintain the frame in a position wherein the leg members extend horizontally outwardly from the pole to provide two spaced points of support for at coaxial cable, being installed to prevent kinking or bending of the cable. It is believed that the L-shaped members are clearly distinguishable from applicant's use of a single dolly in stringing a cable around deflections or building angles, among other patentable distinctions.
It can readily be appreciated that these references, either singly or in combination, are not concerned with and do not suggest or infer the teachings of the present invention for eliminating the need for both small and large dolly pulleys in pulling large conductive cables and similar objects onto structures having deflections or angle structures.